Mycelium: with hyphae 3-6 µm wide, producing short branches 10-20 µm long which bear brown, lobed (often deeply so), hyphopodia which are very variable in shape but to 25 µm diam when ± isodiametric, with a clear dot at the place of host penetration.
Anamorph: not known.
Teleomorph: Ascomata 300-400 µm diam, neck 150-180 µm long and to 80 µm diam, immersed, joined to brown mycelium within the host leaf sheath cavity. Peridium 30-40 µm thick, of 6-8 layers of cells, individual cells 8-10 x 2-5 µm. Asci 140-180 x 10-14 µm, elongate-clavate, apical ring small but definite, lower part (10-13 µm) free from ascospores. Ascospores (80-)120-150(-155) x 2-3 µm, filiform, usually slightly curved, with rounded apex and narrower rounded base, hyaline to faintly tinged, mostly 7- to 8-septate, in parallel or very slightly twisted within the ascus, contents granular.